A conventional power supply controller includes a high-power semiconductor switch element (such as a power MOSFET) to be provided in a power supply path between a power source and a load. The power supply controller controls current supply to the load by turning on and off the semiconductor switch element. Furthermore, the power supply controller uses the semiconductor switch element in place of a mechanical current fuse as a fuse for protecting the power supply path to the load from overcurrent etc. If overcurrent passes, the power supply controller controls potential at a control terminal of the semiconductor switch element using a control circuit so as to turn off the semiconductor switch element, thereby shutting off power supply (see Patent Document 1).    (Patent Document 1) Japanese Unexamined Patent Application Publication No. 2000-315588